Process for producing amino compounds of the quinoline series



Patented July 13, 1937 UNI ED- STATES PATENT OFFICE PROCESS FOR PRODUCING AMINO COM- POUNDS OF THE QUINOLINE SERIES Werner Zerweck and Wilhelm Kunze, Frankforton-the-Main-Fechenheim, Germany, assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application April 15, 1935, Serial No. 16,507. In Germany April 24, 1934 2 Claims.

Our invention relates to a process for producing amino compounds of the quinoline series which consists in reacting with compounds of the general formula:

'" hydrogenatom attached. to the nitrogen atom,

on quinoline sulfonic acids containing the sulfonic acid groups in thepyridine nucleus. The reaction is adyantageously carried out by heating the components with the addition of a condensing agent of the type of zinc chloride or copper. In this manner the aminoquinolines and their N-substitution products whichare partly new compounds are obtained with an excellent yield.

Compared with the hitherto known methods of preparing the said compounds by starting from the corresponding halogen-compounds the pres ent ,processis, superior owing to the fact that in all cases, even'when 'using amines as components, the reaction can be carried out in an aqueous me diuni and at lower temperatures so that the formation of undesired .by-products particularly of the corresponding, hydroxy-quinolines can be avoided.

g 'In orderto furtherillustrate our inventionythe following examples are given, the parts being by weight and all temperatures in centigrade degrees. We wish it however to be understood that our invention is not limited to the particular products nor reaction conditions mentioned therein.

Example 1 In a pure state, when recrystallized from water, it melts at 127 C.

Example 2 5 parts of 4-methylquinoline-2-sulfonic acid are mixed with 25 parts of an ammonia solution of 25% strength and 1 part of zinc chloride and the mixture is heated for some hours at 130 to 135 C. The reaction product is filtered ofi when cool. When recrystallized from water the lepidine of the formula:

N H: N a

is obtained in a pure state, melting at 130 to 131 C.

Example 3 NH: N

'for which the theoretical nitrogen-content is 26;4%. I

The'quinoline 2.4-,disulfonic acid used as starting material may be obtained by heating 2.4-dichloro-quinoline with an aqueous sodium sulfite solution. In contradistinction to the monosulfonic acids the quinoline-2.4-disulfonic acid is easily soluble in water.

Example 4 A mixture of 12 parts of quinoline-4-sulfonic acid and 60 parts of an ammonia solution of 25% strength is heated at about 130 C. for 15 hours. The reaction product which primarily separates as an oil solidifies after some time. Recrystallized til ' which is extracted with ether.

from water the 4-amino-quinoline thus formed of the formula:

NHz

melts at 70 C., it contains in the crystallized form one mole of crystal water.

Example 5 which was hitherto unknown, solidifies. It crystallizes from dilute methylalcohol in the form of colorless prisms of 70 to 71 C. melting point.

Example 6 6 parts. of quinoline-Z-sulfonic acid are mixed with 9 parts of 1-diethylamino-4amino-npentane of the formula 20 parts of water and 1 part of zinc chloride and the mixture is heated for some hours at about 140 C. An oily reaction product is obtained After evaporation of the ether to the residue a benzenic solution of picric acid is added. The picrate separates primarily in a resinous state and solidifies when stirred with alcohol. It may be recrystallized from glacial acetic acid in the form of dark yellow crystals of 159 to 160 C. melting point.

By decomposing the picrate with hydrochloric acid the hitherto unknown base of the formula:

NJNHLFH-OHzOH2-OHzN(CgH5)z OH: is obtained as a viscous colorless oil.

Example 7 H CzHs is obtained as a viscous almost colorless oil the picrate of which forms greenish yellow needles of 155 to 157 C. melting point.

When condensing the said sulfonic acid with asymmetrical diethyl-ethylenediamine (Czl-ls) 2 NCH2CH 2- -NI-Iz,

the reaction product of the formula:

NH-CH2-CHPN O2H5M represents an almost colorless oil soluble in ether, the picrate of which melts at 189 to 190 C. The condensation with 1-diethylamino-2-hydroxy-3 aminopropane yields a product of the formula:

being a viscous oil, insoluble in ether, but soluble in chloroform, the picrate of which melts at 162 C.

Example 8 13 parts of 4methylquinoline-2-sulfonic acid are heated for some hours at to C. with 30 parts of an aqueous solution of cyclohexylamine of about 50% strength with the addition of 0.3 part of copper bronze. By extracting the reaction mass with other the reaction product is obtained as a crystalline substance. When recrystallized from methylalcohol the hitherto unknown 2-cyclohexylamino-4-methylquinoline of the formula:

forms almost colorless prisms of 116 to 117 C. melting point.

Example 9 melts when recrystallized from alcohol at 128 C.

Example 10 A mixture of ,13 parts of 4-methylquinoline-2- sulfonic acid, 14 parts of e-naphthylamine, parts of water and 0.3 part -of copper bronze is heated for some hours at-135 to 140 C. When cool the reaction product is filtered off, washed out and dried. In order to remove unchanged p-naphthylamine the raw product is recrystaliized from monochlorobenzene. The 2-p-naphthylamino-4-methy1quino1ine of the formula:

CHa

thus obtained, which was unknown hitherto, forms colorless needles of 164 to 165 C. melting point.

We claim:

1. Process for producing amino-compounds of the quinoline series which comprises heating mixtures of compounds of the general formula:

wherein R1 means hydrogen, R2 hydrogen or an aliphatic radicle and R3 hydrogen or an aliphatic, cycloaliphatic or aromatic hydrocarbon radicle of the benzene or naphthalene series, and quinoline sulfonic acids of the formula:

' wherein n stands for one of the numbers 2 to 5 and X means hydrogen or hydroxyl, and quinoline sulfonic acids of the formula:

at temperatures above 100 C.

WERNER ZERWECK. WILI-IELM KUNZE. 

